Given that it seems to work fine as a Disk ][ P6A PROM replacement, here is my release of the GAL22V10 conversion of said PROM: https://codeberg.org/hkzlab/Apple_Disk-II_PROM_GAL_conversion

It's faster and smaller than an EPROM.

As usual, if you feel like it, throw me a few credits via Ko-Fi ☕. They REALLY help.

My intention would be to design a Disk ][ clone (yes. ANOTHER CLONE!) around this, but I want to do it after I understand if I can replace the 74LS323 with a '299 (not that it is a binding choice in the design: you can use the same footprint and just reprogram the PLD to support one or the other).

#apple2 #disk2

More #floppy stuff: Today I did basic tests of the Apple Disk ][ connector on the Floppsy prototype using our GreaseWeazle compatible firmware.

It requires a small change to greaseweazle host software to restore support for --drive APPLE2, and you have to specify "--tracks step=4" to move the correct distance between tracks. (this is better than the previous way I handled this, where there were two different --drive arguments for full & quarter stepping! Rarely, especially when archiving copy-protected media, you may want an image of all the half-tracks or even all the quarter-tracks)

My test floppy reads back some valid sectors (it's consistent which ones on any given track), but also encounters many read errors. Given that this is just the floppy that happened to be in the drive, idk what bad things might have happened to it before I shelved it last year, so I'm not too worried.

I didn't test flux writing but I guess I should treat this unlabeled floppy as a scratch disk and try it.

Pull request is open: https://github.com/adafruit/Adafruit_Floppy/pull/37

#floppy #archiving #greaseweazle #retrocomputing #apple #apple2 #disk2 #appleii #diskii #digitalpreservation